1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * List pending timers
4 *
5 * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
6 */
7
8 #include <linux/proc_fs.h>
9 #include <linux/module.h>
10 #include <linux/spinlock.h>
11 #include <linux/sched.h>
12 #include <linux/seq_file.h>
13 #include <linux/kallsyms.h>
14 #include <linux/nmi.h>
15
16 #include <linux/uaccess.h>
17
18 #include "tick-internal.h"
19
20 struct timer_list_iter {
21 int cpu;
22 bool second_pass;
23 u64 now;
24 };
25
26 /*
27 * This allows printing both to /proc/timer_list and
28 * to the console (on SysRq-Q):
29 */
30 __printf(2, 3)
SEQ_printf(struct seq_file * m,const char * fmt,...)31 static void SEQ_printf(struct seq_file *m, const char *fmt, ...)
32 {
33 va_list args;
34
35 va_start(args, fmt);
36
37 if (m)
38 seq_vprintf(m, fmt, args);
39 else
40 vprintk(fmt, args);
41
42 va_end(args);
43 }
44
45 static void
print_timer(struct seq_file * m,struct hrtimer * taddr,struct hrtimer * timer,int idx,u64 now)46 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
47 int idx, u64 now)
48 {
49 SEQ_printf(m, " #%d: <%pK>, %ps", idx, taddr, timer->function);
50 SEQ_printf(m, ", S:%02x", timer->state);
51 SEQ_printf(m, "\n");
52 SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
53 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
54 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)),
55 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now),
56 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now));
57 }
58
59 static void
print_active_timers(struct seq_file * m,struct hrtimer_clock_base * base,u64 now)60 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
61 u64 now)
62 {
63 struct hrtimer *timer, tmp;
64 unsigned long next = 0, i;
65 struct timerqueue_node *curr;
66 unsigned long flags;
67
68 next_one:
69 i = 0;
70
71 touch_nmi_watchdog();
72
73 raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
74
75 curr = timerqueue_getnext(&base->active);
76 /*
77 * Crude but we have to do this O(N*N) thing, because
78 * we have to unlock the base when printing:
79 */
80 while (curr && i < next) {
81 curr = timerqueue_iterate_next(curr);
82 i++;
83 }
84
85 if (curr) {
86
87 timer = container_of(curr, struct hrtimer, node);
88 tmp = *timer;
89 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
90
91 print_timer(m, timer, &tmp, i, now);
92 next++;
93 goto next_one;
94 }
95 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
96 }
97
98 static void
print_base(struct seq_file * m,struct hrtimer_clock_base * base,u64 now)99 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
100 {
101 SEQ_printf(m, " .base: %pK\n", base);
102 SEQ_printf(m, " .index: %d\n", base->index);
103
104 SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution);
105
106 SEQ_printf(m, " .get_time: %ps\n", base->get_time);
107 #ifdef CONFIG_HIGH_RES_TIMERS
108 SEQ_printf(m, " .offset: %Lu nsecs\n",
109 (unsigned long long) ktime_to_ns(base->offset));
110 #endif
111 SEQ_printf(m, "active timers:\n");
112 print_active_timers(m, base, now + ktime_to_ns(base->offset));
113 }
114
print_cpu(struct seq_file * m,int cpu,u64 now)115 static void print_cpu(struct seq_file *m, int cpu, u64 now)
116 {
117 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
118 int i;
119
120 SEQ_printf(m, "cpu: %d\n", cpu);
121 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
122 SEQ_printf(m, " clock %d:\n", i);
123 print_base(m, cpu_base->clock_base + i, now);
124 }
125 #define P(x) \
126 SEQ_printf(m, " .%-15s: %Lu\n", #x, \
127 (unsigned long long)(cpu_base->x))
128 #define P_ns(x) \
129 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
130 (unsigned long long)(ktime_to_ns(cpu_base->x)))
131
132 #ifdef CONFIG_HIGH_RES_TIMERS
133 P_ns(expires_next);
134 P(hres_active);
135 P(nr_events);
136 P(nr_retries);
137 P(nr_hangs);
138 P(max_hang_time);
139 #endif
140 #undef P
141 #undef P_ns
142
143 #ifdef CONFIG_TICK_ONESHOT
144 # define P(x) \
145 SEQ_printf(m, " .%-15s: %Lu\n", #x, \
146 (unsigned long long)(ts->x))
147 # define P_ns(x) \
148 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \
149 (unsigned long long)(ktime_to_ns(ts->x)))
150 # define P_flag(x, f) \
151 SEQ_printf(m, " .%-15s: %d\n", #x, !!(ts->flags & (f)))
152
153 {
154 struct tick_sched *ts = tick_get_tick_sched(cpu);
155 P_flag(nohz, TS_FLAG_NOHZ);
156 P_flag(highres, TS_FLAG_HIGHRES);
157 P_ns(last_tick);
158 P_flag(tick_stopped, TS_FLAG_STOPPED);
159 P(idle_jiffies);
160 P(idle_calls);
161 P(idle_sleeps);
162 P_ns(idle_entrytime);
163 P_ns(idle_waketime);
164 P_ns(idle_exittime);
165 P_ns(idle_sleeptime);
166 P_ns(iowait_sleeptime);
167 P(last_jiffies);
168 P(next_timer);
169 P_ns(idle_expires);
170 SEQ_printf(m, "jiffies: %Lu\n",
171 (unsigned long long)jiffies);
172 }
173 #endif
174
175 #undef P
176 #undef P_ns
177 SEQ_printf(m, "\n");
178 }
179
180 #ifdef CONFIG_GENERIC_CLOCKEVENTS
181 static void
print_tickdevice(struct seq_file * m,struct tick_device * td,int cpu)182 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
183 {
184 struct clock_event_device *dev = td->evtdev;
185
186 touch_nmi_watchdog();
187
188 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode);
189 if (cpu < 0)
190 SEQ_printf(m, "Broadcast device\n");
191 else
192 SEQ_printf(m, "Per CPU device: %d\n", cpu);
193
194 SEQ_printf(m, "Clock Event Device: ");
195 if (!dev) {
196 SEQ_printf(m, "<NULL>\n");
197 return;
198 }
199 SEQ_printf(m, "%s\n", dev->name);
200 SEQ_printf(m, " max_delta_ns: %llu\n",
201 (unsigned long long) dev->max_delta_ns);
202 SEQ_printf(m, " min_delta_ns: %llu\n",
203 (unsigned long long) dev->min_delta_ns);
204 SEQ_printf(m, " mult: %u\n", dev->mult);
205 SEQ_printf(m, " shift: %u\n", dev->shift);
206 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev));
207 SEQ_printf(m, " next_event: %Ld nsecs\n",
208 (unsigned long long) ktime_to_ns(dev->next_event));
209
210 SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event);
211
212 if (dev->set_state_shutdown)
213 SEQ_printf(m, " shutdown: %ps\n",
214 dev->set_state_shutdown);
215
216 if (dev->set_state_periodic)
217 SEQ_printf(m, " periodic: %ps\n",
218 dev->set_state_periodic);
219
220 if (dev->set_state_oneshot)
221 SEQ_printf(m, " oneshot: %ps\n",
222 dev->set_state_oneshot);
223
224 if (dev->set_state_oneshot_stopped)
225 SEQ_printf(m, " oneshot stopped: %ps\n",
226 dev->set_state_oneshot_stopped);
227
228 if (dev->tick_resume)
229 SEQ_printf(m, " resume: %ps\n",
230 dev->tick_resume);
231
232 SEQ_printf(m, " event_handler: %ps\n", dev->event_handler);
233 SEQ_printf(m, "\n");
234 SEQ_printf(m, " retries: %lu\n", dev->retries);
235
236 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
237 if (cpu >= 0) {
238 const struct clock_event_device *wd = tick_get_wakeup_device(cpu);
239
240 SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>");
241 }
242 #endif
243 SEQ_printf(m, "\n");
244 }
245
timer_list_show_tickdevices_header(struct seq_file * m)246 static void timer_list_show_tickdevices_header(struct seq_file *m)
247 {
248 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
249 print_tickdevice(m, tick_get_broadcast_device(), -1);
250 SEQ_printf(m, "tick_broadcast_mask: %*pb\n",
251 cpumask_pr_args(tick_get_broadcast_mask()));
252 #ifdef CONFIG_TICK_ONESHOT
253 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n",
254 cpumask_pr_args(tick_get_broadcast_oneshot_mask()));
255 #endif
256 SEQ_printf(m, "\n");
257 #endif
258 }
259 #endif
260
timer_list_header(struct seq_file * m,u64 now)261 static inline void timer_list_header(struct seq_file *m, u64 now)
262 {
263 SEQ_printf(m, "Timer List Version: v0.10\n");
264 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
265 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
266 SEQ_printf(m, "\n");
267 }
268
sysrq_timer_list_show(void)269 void sysrq_timer_list_show(void)
270 {
271 u64 now = ktime_to_ns(ktime_get());
272 int cpu;
273
274 timer_list_header(NULL, now);
275
276 for_each_online_cpu(cpu)
277 print_cpu(NULL, cpu, now);
278
279 #ifdef CONFIG_GENERIC_CLOCKEVENTS
280 timer_list_show_tickdevices_header(NULL);
281 for_each_online_cpu(cpu)
282 print_tickdevice(NULL, tick_get_device(cpu), cpu);
283 #endif
284 return;
285 }
286
287 #ifdef CONFIG_PROC_FS
timer_list_show(struct seq_file * m,void * v)288 static int timer_list_show(struct seq_file *m, void *v)
289 {
290 struct timer_list_iter *iter = v;
291
292 if (iter->cpu == -1 && !iter->second_pass)
293 timer_list_header(m, iter->now);
294 else if (!iter->second_pass)
295 print_cpu(m, iter->cpu, iter->now);
296 #ifdef CONFIG_GENERIC_CLOCKEVENTS
297 else if (iter->cpu == -1 && iter->second_pass)
298 timer_list_show_tickdevices_header(m);
299 else
300 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
301 #endif
302 return 0;
303 }
304
move_iter(struct timer_list_iter * iter,loff_t offset)305 static void *move_iter(struct timer_list_iter *iter, loff_t offset)
306 {
307 for (; offset; offset--) {
308 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
309 if (iter->cpu >= nr_cpu_ids) {
310 #ifdef CONFIG_GENERIC_CLOCKEVENTS
311 if (!iter->second_pass) {
312 iter->cpu = -1;
313 iter->second_pass = true;
314 } else
315 return NULL;
316 #else
317 return NULL;
318 #endif
319 }
320 }
321 return iter;
322 }
323
timer_list_start(struct seq_file * file,loff_t * offset)324 static void *timer_list_start(struct seq_file *file, loff_t *offset)
325 {
326 struct timer_list_iter *iter = file->private;
327
328 if (!*offset)
329 iter->now = ktime_to_ns(ktime_get());
330 iter->cpu = -1;
331 iter->second_pass = false;
332 return move_iter(iter, *offset);
333 }
334
timer_list_next(struct seq_file * file,void * v,loff_t * offset)335 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
336 {
337 struct timer_list_iter *iter = file->private;
338 ++*offset;
339 return move_iter(iter, 1);
340 }
341
timer_list_stop(struct seq_file * seq,void * v)342 static void timer_list_stop(struct seq_file *seq, void *v)
343 {
344 }
345
346 static const struct seq_operations timer_list_sops = {
347 .start = timer_list_start,
348 .next = timer_list_next,
349 .stop = timer_list_stop,
350 .show = timer_list_show,
351 };
352
init_timer_list_procfs(void)353 static int __init init_timer_list_procfs(void)
354 {
355 struct proc_dir_entry *pe;
356
357 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops,
358 sizeof(struct timer_list_iter), NULL);
359 if (!pe)
360 return -ENOMEM;
361 return 0;
362 }
363 __initcall(init_timer_list_procfs);
364 #endif
365